Auto-complete xxh host name from ssh config

[athityakumar]

xxh has been awesome so far with it's core functionality - but I need to type in the exact host names from ssh config as of now. Is it possible to auto-complete this with TAB-key support?

xxh host-prefix[TAB]

host-prefix-1
host-prefix-2
host-prefix-3

🏅 Solutions:

➡️ Bash and Xonsh on Ubuntu - #82 (comment)

➡️ Zsh - #82 (comment)

➡️ Fish - #82 (comment)

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[anki-code]

The auto-complete is depend on the shell and OS you use. But some shells like xonsh can get the completions from bash as well.

In Ubuntu 20.04 I just added the same completion as ssh to bash and it works in xonsh the same way:

$ sudo bash
# cat > /etc/bash_completion.d/xxh_complete <<'COMPLETION'
_xxh() {
    local cur prev words cword
    _init_completion || return
   _known_hosts_real -a "$cur"
} && complete -F _xxh xxh
COMPLETION

After relogin:

bash$ complete | grep xxh
complete -F _xxh xxh

bash$ xxh host-prefix[TAB]
host-prefix-1
host-prefix-2
host-prefix-3

bash$ xonsh
xonsh$ xxh host-prefix[TAB]
host-prefix-1
host-prefix-2
host-prefix-3

The best way to solve it is to understand how your shell and OS works with auto-complete, get the ssh default auto-complete and post here the solution for xxh. As I did for Ubuntu.

[athityakumar]

My current setup is Mac OS & zsh shell - any idea how I can add custom completion of hosts for xxh locally?

[athityakumar]

Also, can you guide me on how I can contribute this auto-completion as something that works out-of-the-box automatically upon installing xxh?

[anki-code]

My current setup is Mac OS & zsh shell - any idea how I can add custom completion of hosts for xxh locally?

Sorry I'm not the user of zsh and MacOS.
This could help:

• Bash completion for commands in Mac OS X
• Can a Bash tab-completion script be used in zsh?

Also, can you guide me on how I can contribute this auto-completion as something that works out-of-the-box automatically upon installing xxh?

Good question. I have no answer now.

[chitoku-k]

This could be easily achieved by adding the following config:

#compdef xxh

_xxh() {
    service=ssh _ssh $@
}

_xxh

Put this file to somewhere your environment autoloads, which you can check $fpath for the exact location. Probably I can add one to this repo?

[anki-code]

@chitoku-k for what OS and shell type your solution?

[chitoku-k]

@anki-code This solution only works for Zsh as it has built-in support for SSH completion (probably for any OS, at least it works in macOS and Linux).
https://github.com/zsh-users/zsh/blob/zsh-5.8/Completion/Unix/Command/_ssh

[anki-code]

@chitoku-k If you can write the complete script to install xxh autocomplete for zsh it will be great! Something like this on bash or zsh:

#!/bin/bash
mkdir -p ~/.config/xxh/
echo ' ... compef xxh ... ' > ~/.config/xxh/autocomplete-zsh
echo 'source ~/.config/xxh/autocomplete-zsh' >> ~/.zshrc
echo 'Please restart zsh'

And place it to the repo to autocomplete/install-xxh-autocomplete-zsh.sh.

[chitoku-k]

@anki-code For homebrew, it has built-in support for installing package-specific completion script described in Homebrew Shell Completion, which is quite handy if we can enable it in installation steps. I can somehow contribute to this.

[anki-code]

@athityakumar @chitoku-k Are you using argcomplete or alternatives? One of the way is to add it to xxh.

[chitoku-k]

@anki-code I am not quite familiar with that. Presumably we got to integrate with the existing completion for ssh command at least.

[Gorthog]

If you want hosts completion from ssh config file when using fish add this to your ~/.config/fish/config.fish file:

read -alz -d \n contents <~/.ssh/config
set hosts (string replace -rfi '^\s*Host\s+(\S.*?)\s*$' '$1' -- $contents | string split " " | string match -rv '[\*\?]' | string join ' ')
complete -c xxh -f -a $hosts

this is a simplified version of what fish completions for ssh. you can see the source here